Kazimierz Kuratowski in nLab

Kazimierz Kuratowski (b. February 2, 1896, d. June 18, 1980) was a Polish mathematician who worked primarily in general topology and mathematical logic.

He is probably best known for a celebrated theorem in graph theory: that a graph GG is planar iff neither the complete graph K 5K_5 on 55 vertices nor the complete bipartite graph K 3,3K_{3, 3} on a pair of 33-element sets appear as edge subdivisions of subgraphs of GG (closely related to Wagner’s theorem that this is the case iff neither K 5K_5 nor K 3,3K_{3, 3} appear as graph minors of GG).

• wikipedia entry

Selected writings

Early discussion of topology/topological spaces:

• Kazimierz Kuratowski, Sur l’opération Ā de l’Analysis Situs, Fundamenta Mathematicae 3 (1922) 182–199 [doi:10.4064/fm-3-1-182-199]

See also:

• C. Kuratowski, Sur la notion d’ensemble fini , Fund. Math. I (1920) pp.130-131. (pdf)

• Casimir Kuratowski (1930), “Sur le problème des courbes gauches en Topologie”, Fundamenta Mathematicae, 15 (1):271-283. (eudml)

• closed subspace

• finite set